The following relates to printing systems. It finds particular application in conjunction with scheduling pages in print or marking systems with multiple printing engines for improving the image consistency of the pages within a booklet and will be described with the particular reference thereto. However, it is to be appreciated that the present exemplary embodiments are also amenable to other like applications.
Typically, in image printing systems, it is desirable that a printed image closely match, or have similar aspects or characteristics to a desired target or input image. However, many factors, such as temperature, humidity, ink or toner age, and/or component wear, tend to move the output of a printing system away from the ideal or target output. For example, in xerographic marking engines, system component tolerances and drifts, as well as environmental disturbances, may tend to move an engine response curve (ERC) away from an ideal, desired or target engine response and toward an engine response that yields images that are lighter or darker than desired.
In the printing systems, which include multiple printing engines, the importance of engine response control or stabilization is amplified. Subtle changes that may be unnoticed in the output of a single marking engine can be highlighted in the combined output of a multi-engine image marking system.
One problem arises when the facing pages of an opened booklet produced by a multi-engine printing system are printed by different engines. For instance, the left-hand page in an open booklet may be printed by a first print engine while the right-hand page is printed by a second print engine. The first print engine may be printing images in a manner slightly darker than the ideal and well within a single engine tolerance; while the second print engine may be printing images in a manner slightly lighter than the ideal and also within the single engine tolerance. While a user might not ever notice the subtle variations when reviewing the output of either engine alone, when the combined output is compiled and displayed in the open booklet on adjacent facing pages, the variation in intensity from one print engine to another may become noticeable and be perceived as an issue of quality by a user. One approach to correct this problem is to print the facing pages of the document by the same printing engine.
However, such an approach is problematic in some cases. For example, the user might be riffling through a stapled booklet each page of which, for example, includes the same colored image in the same portion of each right-hand page, e.g. a company logo. For instance, the facing pages are printed by the same engine, therefore, the right-hand pages are printed by different print engines. When the combined output is compiled and displayed adjacently page after page, the variation in the color intensity from one right-hand page to another may become noticeable and objectionable by the user.
There is a need for methods and apparatuses that overcome the aforementioned problems and others.